Anchoring device with resilient tie means for automatic pre-anchoring



United States Patent O ANCHORING DEVICE WITH RESILIENT TIE MEANS FORAUTOMATIC PRE-ANCHORING Andr Durget, Saverne, France, assigner toAnciens Etablissements Goldenherg & Cie, Zornhotf, France, a

French body corporate Filed Mar. 9, 1961), Ser. No. 13,788 Claimspriority, application France Mar. 17, 1959 3 Claims. (Cl. 85--2.4)

The present invention relates to `anchoring devices and, moreparticularly, to anchoring devices of the type comprising a traction rodcarrying one or more groups of cams cooperating with correspondinggroups of ramps provided on shells enclosing the rod.

Such anchoring devices have multiple uses, in particular for settingobjects in walls, bedding down machines and any other applicationsrequiring the integral securement of any piece on any assembly capableof having a hole formed therein. Moreover, such devices are extensivelyused in mines for bolting the roof, the `facings and the walls thereof.

It has already been proposed lto provide such anchoring devices with aresilient means bearing simultaneously on the shells and the tractionrod, in order to effect a selfoperating pre-anchoring of the deviceIupon its insertion into the bore.

By self-operated pre-anchoring it is meant that the anchoring deviceshould become self sustaining as soon as it has been inserted in thebore and prior to any expansion of the device effected by means of atraction exerted on said rod.

However, all previously known devices `are comparatively complex and areaccordingly objectionable from the point of view of the increased costthereof.

The invention aims at overcoming the aforesaid drawback by providing an-anchoring device of the above-mentioned type, achieving theself-operated pre-anchoring by the provision of extremely simple means.

This device is essentially characterized in that the resilient meansproviding the said self-operated pre-anchoring is comprised by aresilient tie bearing by both ends thereof on the shells and extendingthrough an aperture provided in the traction rod or one of the camscarried thereon.

The simplicity of the device providing the self-operated pre-anchoringis evident from the above-given definition thereof. On the other hand,its efficiency can be explained as follows: when the `anchoring deviceis inserted into a bore by exerting a'push on the traction rod thereof,the said resilient tie is tensioned and, when the pushing isdiscontinued, returns the rod between the two shells; these shells arethus spread apart by the cams carried on the rod and are sturdilypressed against the wall of the bore, thus achieving an automaticself-maintenance of the anchoring device.

Further features and advantages of the present invention will becomeapparent from the ensuing description, when read in connection with theaccompanying drawing, given merely by way of example and in which:

FIG. 1 is an exploded view of one embodiment of the anchoring devicedesigned in accordance with the invene tion;

FIGS. 2 and 3 are longitudinal sectional views of said anchoring device,shown as positioned in a bore and at two successive operational stagesthereof; and

FIG. 4 is a view similar to that of FIG. 2 but showing an alternativearrangement of the anchoring device.

In accordance with the embodiment `shown in FIGS. 1 to 3 of the drawing,the anchoring device comprises two shells 1 and 2 forming whenjuxtaposed a segmented tube, in which position they are maintained by aresilient ICC tie 3. The thus-formed tube is adapted to enclose anassembly consisting of a traction rod and cams operative to expand thesegmented tube.

This assembly comprises, starting at the top, a first group of camsprovided by the side faces 4 of a wedge member A, a second set of camsprovided by the side faces 5 of a second wedge member B, both Wedges Aand B being connected by a cross-sectionally reduced portion 6, havingon the sidewalls thereof reinforcing blocks 7 obtained by forging. Theunit B is unitary at its lower portion with a stirrup or bracket 8having its two arms disposed on either side of said wedge B, and on thelower portion of which is provided a nut 9. This nut has screwed thereina threaded end of the traction rod, proper, the other end of this rod10, which is likewise threaded, having screwed thereon a nut 11retaining a back plate 12 mounted on the rod 10.

The shells 1 and 2 are arranged so as to be adapted to the variouscomponents of the above described assembly. Thus, the longitudinal edgesof the shells each comprise an arcuate cut-out portion 13 to accommodatethe reinforcing blocks 7, and a second rectilinear cut-out portion 14adapted to have the arms of the bracket S located therein.

Moreover, each shell has formed in the inner wall thereof a first ramp1S adapted to cooperate with the corresponding face 4 of the block A,and a second ramp 16 adapted to cooperate with the corresponding face 5of the block B.

It will be appreciated that each ramp 16 has formed therein, along thelongitudinal axis thereof, a groove 17 into which can be engaged aprojection 18 integrally formed on the corresponding -face 5, so as -toprovide a guiding means for the block B.

Intermediate the ramps 15 and 16 there is provided a window 19 formed inthe shells 1 and 2, with the view to afford a passage for the upper endof the block B and for the projections 18, when the shells are in theminimum spreading position thereof (see FIG. 2).

The outer wall of `the shells has further the usual notches 20 formedthereon in order to grip the wall of the bore.

Finally, in accordance with an essential feature of the invention, thebase of the block B has bored therein a transverse aperture 21 throughwhich extends an endless resilient tie 22 having its ends bearingrespectively onto the base of each shell. To this end, each shell isprovided at the base thereof with a gripping finger or lug 23 of curvedcross-section and into which is inserted the tie 22. The inner wall ofthe shell bases is further provided with a groove or notch 24 to preventthe tie 22 from being sheared by the bases of the shells.

The operation of the device will now be described with particularreference to FIGS. 2 and 3 of the drawing.

In order to locate the anchoring device, there is formed a bore F of adiameter substantially equal to the minimum diameter of the anchoringdevice.

When the tube formed by the shells 1 and 2 is at its smallest diameter,the various components of the anchoring device take the relativepositions illustrated in FIG. 2, which are as follows:

The bases of the cam faces 4 are in contact with the ramps 15;

The reinforcing blocks 7 are housed within the recesses 13 and the armsof the stirrup or bracket member 8 are engaged in the recesses 14;

The upper portion of the wedge B with its projections 18 is engaged intothe windows 19;

The resilient tie 22 is in its position o-f maximum ten` sion.

When the anchoring device is introduced into the bore F by exerting apush on the traction rod ll() in the direcaccade-1 tion indicated by thearrow the outer portion of the shells 1 and 2 and the notches 3frictionally engage the wall of the bore, thus exerting a rapid brakingaction on the movement of the shells, whereby the traction rod pursuesits stroke on its own and reaches the position shown in FIG. 2, i.e. theposition corresponding to the minimum diameter of the shells. As hasalready been mentioned, the resilient tie 22 is by then under tension.

Thus, `when the push exerted on the traction rod is discontinued, thelatter is strongly urged by the resilient tie 22 and is lowered betweenthe shells, as can be seen in FIG. 3. In the course of this downwardstroke, the cams 4 and 5 respectively cooperate with the ramps 15 and16, thus causing the shells to be spread apart by an arnount sufcient tobring them into a gripping engagement with the wall of the bore.Accordingly, the anchor device becomes self-sustaining as soon as thetraction rod 16 is released.

Thus an automatic pre-anchoring is achieved. The

device is then ready to have imparted thereto the expansion proper,which is elected in the usual way, i.e. by tightening the nut 11 on therod It). The plate 12 comes to bear against the front face of the boreand thus any additional tightening of the nut 11 causes the traction rodto descend, which in turn causes the cams to be lowered on theirrespective ramps and the shells to be spread apart.

In the course of the expanding process, the resilient tie 22 canjump-off the lugs 23 or be sheared, but this is of no importance sinceit has already fulfilled the function for which it was intended.

It appears from the foregoing description how simple is the means whichprovides, in accordance with the invention, the automatic pre-anchoringof the shells.

It is to be understood that the invention is not conned to thethus-described embodiment thereof, which was given merely by way of anexample.

Thus, for instance, there is illustrated in FIG. 4 a moditication whichdiffers from the foregoing embodiment merely by the following points:

Instead of bearing on the bases of the shells, the tie 22 is xedadjacent the apex thereof. To this end, lugs 23a are provided at theupper portion of the windows 19, whereas the base of the block A hasformed therein a hole 21a having the resilient tie 22 extendedtherethrough.

The operation of the device shown in FIG. 4 is substantially identicalto that ofthe earlier-described arrangement, except that the tensionwhich can be imparted to the tie 22 is smaller than in the rstembodiment.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is:

l. An anchoring device comprising shells constituting a segmented tubeadapted to be inserted into a boreprovided in a wall and dening aninternal chamber, said shells having leading and trailing edges, a unitincluding a traction rod mounted in a longitudinally movable relationship within the chamber in said tube and at least one group of camson said rod, at least one group of ramps on said shells internallythereof for cooperating with said group of cams, traction means at theouter end of said rod to displace the latter axially relative to saidtube and to cause said tube to expand, resilient means holding theshells in assembled relation, a resilient tie extending diametrallythrough said unit via an aperture provided in the latter and spaced fromsaid cams, and a lug on each shell spaced radially inwards of lthe outerperiphery thereof and spaced from the leading edge toward the trailingedge thereof for engaging said tie and supporting the same substantiallywithin said chamber, said tie connecting said shells with one another`and with said traction rod whereby, when the anchoring device isinserted into the bore by a force vexerted on said traction rod, saidresilient tie is tensionedto effect an automatic pre-anchoring of saidanchoring device upon release of said rod.

2. An anchoring device as claimed in claim 1 wherein said resilient tieextends through said group of cams, said aperture being provided in saidgroup of cams.

3. An anchoring device as claimed in claim 1 wherein each shell isprovided with a window and the lug on each shell is positioned in saidwindow.

References Cited in the tile of this patent UNITED STATES PATENTS1,033,447 Mower July 23, 1912 2,825,258 McCabe Mar. 4, 1958 2,832,253Allimann Apr. 29, 1958 2,903,938 Strand Sept. 15, 1959 FOREIGN PATENTS1,171,788 France Jan. 29, 1959

